<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta id='viewport' name="viewport" content="initial-scale=1.0"/>
    <title>metaViewport</title>
</head>
<body>
<span>hello world!</span>
</body>
</html>
<script type="text/javascript">
    function isElementMetaViewport() {
       let beforeWindowInnerWidth = window.innerWidth;

        console.log('beforeWindowInnerWidth'+beforeWindowInnerWidth);
         let viewport = document.getElementById("viewport");
       viewport.content = 'initial-scale=2.0';
       let afterWindowInnerWidth = window.innerWidth;
       console.log('afterWindowInnerWidth' + afterWindowInnerWidth);
       return beforeWindowInnerWidth !== afterWindowInnerWidth;
     }
</script>
<style>
</style>
